Substrate plasma-processing apparatus

ABSTRACT

A substrate plasma-processing apparatus for plasma-processing a surface of an electrode of an organic light emitting device. The substrate plasma-processing apparatus may adjust the distance between a first electrode and a substrate and adjust the distance between a second electrode and the substrate.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.12/774,846, filed on May 6, 2010, and claims priority from and thebenefit of Korean Patent Application No. 10-2009-0039887, filed on May7, 2009 in the Korean Intellectual Property Office, both of which arehereby incorporated by reference for all purpose as if fully set forthherein.

BACKGROUND OF THE INVENTION

1. Field

Aspects of the present invention relate to a substrate plasma-processingapparatus.

2. Discussion of the Background

An organic light emitting display device using an organic light emittingdevice (OLED) has a fast response speed compared to a liquid crystal(LCD) typical of those currently widely used. Organic light emittingdisplay devices are being thought of as the next generation displaydevice because an organic light emitting display device accommodates amoving picture better, has a wider viewing angle due to selflight-emission, and exhibits high brightness.

The OLED includes a pixel electrode, a counter electrode facing thepixel electrode, and an emission layer including an organic materialwhere the emission layer is interposed between the pixel electrode andthe counter electrode. Before depositing the organic material, a surfaceof the pixel electrode (i.e., an anode electrode) is processed usingplasma. The plasma-process with respect to the surface of the pixelelectrode has an effect on light emission efficiency and lifetime of theOLED. That is, if the surface of the pixel electrode is not uniformlyplasma-processed, the brightness of the organic light emitting displaydevice is not uniform and also, the lifetime of the organic lightemitting display device is shortened. Therefore, with respect toplasma-processing the surface of the pixel electrode, plasma uniformityin a plasma-processing apparatus is very important.

SUMMARY

Aspects of the present invention provide a substrate plasma-processingapparatus for constantly maintaining plasma uniformity in a chamber. Anaspect of the present invention provides a substrate plasma-processingapparatus for plasma-processing the surface of a pixel or other displayelectrode formed on a substrate, the substrate plasma-processingapparatus including a chamber having disposed therein the substrate; afirst electrode disposed in the chamber apart from the bottom surface ofthe substrate; a second electrode disposed in the chamber apart from thetop surface of the substrate; and a distance adjusting unit adjustingthe distance between the first electrode and the substrate or thedistance between the second electrode and the substrate.

According to an aspect of the invention, the distance adjusting unit mayadjust the distance between the first electrode and the substrate byraising or lowering the substrate.

According to an aspect of the invention, the distance adjusting unit mayadjust the distance between the second electrode and the substrate byraising or lowering the second electrode.

Another aspect of the present invention provides a substrateplasma-processing apparatus for plasma-processing the surface of a pixelor other display electrode of an organic light emitting device, thesubstrate plasma-processing apparatus including a chamber; a distanceadjusting unit for supporting and moving the substrate in the chamber; afirst electrode disposed below and apart from the substrate; and asecond electrode facing the first electrode by being disposed above andapart from the substrate; wherein the distance adjusting unit adjuststhe distance between the substrate and the first electrode or thedistance between the substrate and the second electrode.

According to an aspect of the invention, the distance adjusting unit mayinclude a substrate supporting unit supporting the substrate; asupporting bar coupled with the substrate supporting unit in a directionperpendicular to the substrate; and an actuator vertically raising orlowering the supporting bar.

According to an aspect of the invention, the actuator may increase thedistance between the substrate and the first electrode by moving thesupporting bar outside the chamber.

According to an aspect of the invention, the actuator may decrease thedistance between the substrate and the first electrode by moving thesupporting bar inside the chamber.

According to an aspect of the invention, the second electrode may besupported by the supporting bar and may be disposed above and apart fromthe substrate.

According to an aspect of the invention, the distance between thesubstrate and the second electrode may be maintained constant while thesubstrate is raised or lowered.

According to an aspect of the invention, the second electrode may befixed to the supporting bar.

According to an aspect of the invention, when the substrate is raised,the distance between the substrate and the first electrode may increaseand the distance between the substrate and the second electrode maydecrease.

According to an aspect of the invention, when the substrate is lowered,the distance between the substrate and the first electrode may decreaseand the distance between the substrate and the second electrode mayincrease.

According to an aspect of the invention, the substrate supporting unitand the supporting bar may be formed of an insulating material.

According to an aspect of the invention, the substrate supporting unitand the supporting bar may be formed of a ceramic material.

According to an aspect of the invention, the ceramic may include alumina(Al₂O₃).

According to an aspect of the invention, the substrate plasma-processingapparatus may further include a first insulating member disposed betweenthe substrate supporting unit and the supporting bar, and the firstinsulating member may couple the substrate supporting unit and thesupporting bar.

According to an aspect of the invention, the substrate plasma-processingapparatus may further include a first cover unit externally surroundingthe first insulating member.

According to an aspect of the invention, the first cover unit may beformed of ceramic. The first insulating member may be formed of apolymer.

According to an aspect of the invention, the substrate supporting unitand the supporting bar may be formed of a metal.

According to an aspect of the invention, the substrate plasma-processingapparatus may further include a second insulating member disposedbetween the first electrode and the chamber.

According to an aspect of the invention, the second insulating membermay be formed of a fluoropolymer.

According to an aspect of the invention, the second electrode may begrounded.

According to an aspect of the invention, the may flow in the secondelectrode so as to maintain a temperature of the second electrodeconstant.

According to an aspect of the invention, the first electrode may includeat least one pipe for delivering gas from outside of the chamber; and atleast one shower head for emitting the gas to the chamber.

According to an aspect of the invention, the substrate plasma-processingapparatus may further include at least one flow adjusting valve foradjusting the flow of the gas emitted to the first electrode.

According to an aspect of the invention, the substrate plasma-processingapparatus may further include an inner chamber disposed in the chamber,and the first electrode may be disposed in the inner chamber.

According to an aspect of the invention, the substrate plasma-processingapparatus may further include a third insulating member disposed betweenthe inner chamber and the chamber.

According to an aspect of the invention, the third insulating member maybe formed of a fluoropolymer.

According to an aspect of the invention, the substrate plasma-processingapparatus may further include a second cover unit externally surroundingthe third insulating member.

According to an aspect of the invention, the second cover unit may beformed of a ceramic material.

Additional aspects and/or advantages of the invention will be set forthin part in the description which follows and, in part, will be obviousfrom the description, or may be learned by practice of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

Aspects and advantages of the invention will become apparent and morereadily appreciated from the following description of the embodiments,taken in conjunction with the accompanying drawings of which:

FIG. 1 is a cross-sectional view of a substrate plasma-processingapparatus according to an embodiment of the present invention;

FIG. 2 is a variation of a distance adjusting unit of the substrateplasma-processing apparatus of FIG. 1;

FIG. 3A is a two-dimensional etching map with respect to etching degreeof a mother substrate that is plasma-processed by a conventionalplasma-processing apparatus;

FIG. 3B is a three-dimensional etching map with respect to etchingdegree of a mother substrate that is plasma-processed by a conventionalplasma-processing apparatus;

FIG. 4A is a two-dimensional etching map with respect to etching degreeof a mother substrate that is plasma-processed by the substrateplasma-processing apparatus according to an embodiment of the presentinvention; and

FIG. 4B is a three-dimensional etching map with respect to etchingdegree of a mother substrate that is plasma-processed by the substrateplasma-processing apparatus according to the embodiment of FIG. 4A.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

Reference will now be made in detail to the present embodiments of thepresent invention, examples of which are illustrated in the accompanyingdrawings, wherein like reference numerals refer to the like elementsthroughout. The embodiments are described below in order to explain thepresent invention by referring to the figures.

FIG. 1 is a cross-sectional view of a substrate plasma-processingapparatus 100 according to an embodiment of the present invention.Referring to FIG. 1, the substrate plasma-processing apparatus 100includes a chamber 101, a distance adjusting unit 102, a first electrode104, a second electrode 105, and at least one flow adjusting valve 107.

The distance adjusting unit 102 is disposed in the chamber 101 tosupport a substrate 103 and the second electrode 105. The distanceadjusting unit 102 supports the substrate 103 and the second electrode105, raises or lowers the substrate 103 in the chamber 101, and raisesor lowers the second electrode 105 in the chamber 101. The secondelectrode 105 is disposed above and apart from the substrate 103, andthe first electrode 104 is disposed below and apart from the substrate103. Thus, when the distance adjusting unit 102 raises or lowers thesubstrate 103, the distance S1 between the first electrode 104 and thesubstrate 103, and the distance S2 between the second electrode 105 andthe substrate 103 may be adjusted, or when the distance adjusting unit102 raises or lowers the second electrode 105, the distance S2 betweenthe second electrode 105 and the substrate 103 may be adjusted. Adetailed description thereof will be provided later.

While not required in all aspects, the shown distance adjusting unit 102includes a substrate supporting unit 102 a, a supporting bar 102 b, andan actuator 102 c. The shown substrate supporting unit 102 a supportsthe bottom surface of the substrate 103. The shown substrate supportingunit 102 a is formed of two plates which are individually connected tothe supporting bar 102 b. The two plates of the substrate supportingunit 102 a are disposed apart from each other sufficiently so that thesubstrate 103 is disposed between the two plates. The shown two platesof the substrate supporting unit 102 a support bottom surfaces of bothside portions of the substrate 103, wherein the side portions face eachother. That is, the substrate 103 is disposed between the two plates ofthe substrate supporting unit 102 a so that the bottom surface of thesubstrate 103 faces the first electrode 104, and the top surface of thesubstrate 103 faces the second electrode 105. However, it is understoodthat the supporting unit 102 a can be otherwise constructed, and cansupport other sides of the substrate in addition to, or instead of thesides shown.

An end of the supporting bar 102 b is coupled with the substratesupporting unit 102 a, and a portion of the supporting bar 102 b is inthe chamber 101. Thus, the substrate supporting unit 102 a is disposedin the chamber 101. Referring to FIG. 1, the end of the supporting bar102 b is coupled with the substrate supporting unit 102 a in thedirection perpendicular to the substrate 103, and the other end isconnected to the actuator 102 c disposed outside the chamber 101. Thatis, the portion of the supporting bar 102 b is disposed inside thechamber 101, and another portion of the supporting bar 102 b is disposedoutside the chamber 101, in such a manner that the substrate supportingunit 102 a and the portion of the supporting bar 102 b are disposed inthe chamber 101.

While not required in all aspects, the shown supporting bar 102 b isvertically raised or lowered by the actuator 102 c. Since the end of thesupporting bar 102 b is coupled with the substrate supporting unit 102a, the substrate supporting unit 102 a is raised or lowered when thesupporting bar 102 b is raised or lowered. Thus, according to theraising or the lowering of the supporting bar 102 b, the substrate 103supported by the substrate supporting unit 102 a is raised or lowered.

The actuator 102 c vertically raises or lowers the supporting bar 102 b.As illustrated in FIG. 1, the actuator 102 c is disposed outside thechamber 101. In this case, the actuator 102 c is connected to the otherportion of the supporting bar 102 b, which is outside the chamber 101.However, the position of the actuator 102 c of the substrateplasma-processing apparatus 100 is not limited to the aforementionedposition, and thus, the actuator 102 c may be disposed inside thechamber 101 and connected at other portions of the supporting bar 102 b.

When the actuator 102 c raises the supporting bar 102 b, the supportingbar 102 b moves in the direction toward the outside of the chamber 101so that the substrate supporting unit 102 a which is coupled with theend of the supporting bar 102 b is also raised. Thus, the substrate 103,which is supported by the substrate supporting unit 102 a, is raisedinside the chamber 101. Accordingly, the distance S1 between the firstelectrode 104 and the substrate 103 increases. Conversely, when theactuator 102 c lowers the supporting bar 102 b, the supporting bar 102 bmoves in the direction toward the inside the chamber 101 so that thesubstrate supporting unit 102 a which is coupled with the end of thesupporting bar 102 b is also lowered. Thus, the substrate 103, which issupported by the substrate supporting unit 102 a, is lowered inside thechamber 101. Accordingly, the distance S1 between the first electrode104 and the substrate 103 decreases.

The substrate supporting unit 102 a and the supporting bar 102 b areformed of an insulating material such as a ceramic. The ceramic may bealumina (Al₂O₃). In this manner, the substrate supporting unit 102 a andthe supporting bar 102 b are formed of the insulating material so thatit is possible to prevent arcing from occurring between the substrate103 and the substrate supporting unit 102 a, or between the supportingbar 102 b and the substrate supporting unit 102 a.

As a modified embodiment, a first insulating member 102 d (see FIG. 2)may be disposed between the substrate supporting unit 102 a and thesupporting bar 102 b. FIG. 2 is a diagram of the distance adjusting unit102 of the substrate plasma-processing apparatus of FIG. 1. Referring toFIG. 2, the substrate supporting unit 102 a and the supporting bar 102 bare coupled by a first insulating member 102 d. The first insulatingmember 102 d is a polymer, for example a fluoropolymer. A first coverunit 102 e is disposed to externally surround the first insulatingmember 102 d. The first cover unit 102 e protects the first insulatingmember 102 d from plasma. The substrate supporting unit 102 a and thesupporting bar 102 b are formed of a metal such as aluminum. The firstinsulating member 102 d prevents arcing from occurring between thesubstrate supporting unit 102 a and the supporting bar 102 b.

Referring back to FIG. 1, the first electrode 104 is disposed inside thechamber 101 apart from the bottom surface of the substrate 103. Thefirst electrode 104 is a radio frequency (RF) electrode to which radiofrequency (RF) power is applied. An RF power of about 40 Mhz may beapplied to the first electrode 104.

A surface of the first electrode 104 faces the inside of the chamber101, and the other surface of the first electrode 104 faces the outsideof the chamber 101. At least one shower head 104 a for emitting a gas tothe chamber 101 is disposed on the surface of the first electrode 104,which faces the inside of the chamber 101. At least one pipe 104 b fordelivering a gas from the outside of the chamber 101 to the inside ofthe chamber 101 is disposed on the other surface of the first electrode104, which faces the outside of the chamber 101. A gas such as N₂, O₂,He, Ar, or the like is injected into the first electrode 104. Then, thegas is emitted to the inside of the chamber 101 via the at least oneshower head 104 a of the first electrode 104.

The substrate plasma-processing apparatus 100 further includes at leastone flow adjusting valve 107. Each flow adjusting valve 107 is disposedon one pipe 104 b and adjusts the flow of the gas emitted to the firstelectrode 104.

A second insulating member 106 is disposed between the first electrode104 and the chamber 101. The second insulating member 106 preventsdirect contact between the first electrode 104 and the chamber 101. Thatis, the second insulating member 106 is disposed at side and bottomportions of the first electrode 104 which may contact the chamber 101.In this way, the first electrode 104 and the chamber 101 do not directlycontact each other. Thus, using the second insulating member 106, thefirst electrode 104 and the chamber 101 are insulated from each other sothat it is possible to prevent arcing from occurring between the firstelectrode 104 and the chamber 101. The second insulating member 106 maybe formed of a fluoropolymer.

An inner chamber 108 is disposed in the chamber 101. As shown in FIG. 1,the first electrode 104 is disposed in the inner chamber 108. The topportion of the inner chamber 108 is open.

A third insulating member 109 is disposed between the inner chamber 108and the chamber 101. The third insulating member 109 prevents the innerchamber 108 from directly contacting the chamber 101. By the thirdinsulating member 109, the chamber 101 and the inner chamber 108 areinsulated from each other, and it is possible to prevent arcing fromoccurring between the chamber 101 and the inner chamber 108. The thirdinsulating member 109 may be formed of a fluoropolymer. A second coverunit 110 externally surrounds the third insulating member 109. Thesecond cover unit 110, covering the third insulating member 109,prevents the third insulating member 109 from being directly exposed toplasma. The second cover unit 110 may be formed of a ceramic material.

The second electrode 105 faces the first electrode 104 by being disposedabove and apart from the substrate 103. The second electrode 105 isdisposed in the chamber 101 while being supported by the supporting bar102 b of the distance adjusting unit 102 that supports the substrate103.

The second electrode 105 is disposed above and apart from the substrate103 by being slidably fixed to the supporting bar 102 b. In this manner,in the case where the second electrode 105 is slidably fixed to thesupporting bar 102 b, when the substrate 103 is raised or lowered by thedistance adjusting unit 102, the distance S2 between the substrate 103and the second electrode 105 may increase or decrease while maintaininga constant distance of either the substrate 103 or the second electrode105 relative to the chamber 101.

To be more specific, since the second electrode 105 is slidably fixed tothe supporting bar 102 b, when the substrate 103 is raised, the distanceS2 between the substrate 103 and the second electrode 105 decreases andthe distance S1 between the substrate 103 and the first electrode 104increases. Also, when the substrate 103 is lowered, the distance S2between the substrate 103 and the second electrode 105 increases, andthe distance S1 between the substrate 103 and the first electrode 104decreases. While not required in all aspects, the second electrode 105can be slidably fixed to the supporting bar 102 b while being fixed tothe chamber 101, and/or the second electrode 105 can be fixed to thesupporting bar 102 b using a clamp, which can be loosened to allowadjustment of the distance S2 and tightened to prevent furtheradjustment. However, the invention is not limited thereto.

As another modified embodiment, the second electrode 105 may be disposedat the supporting bar 102 b so as to maintain a constant distance fromthe substrate 103 (i.e., not slidably fixed). In this case, thesubstrate 103 and the second electrode 105 are raised or lowered whilemaintaining the constant distance. Thus, when the substrate 103 israised or lowered, the distance S1 between the substrate 103 and thefirst electrode 104 increases or decreases but the distance between thesubstrate 103 and the second electrode 105 is constant. In the casewhere the distance between the substrate 103 and the second electrode105 has to be changed when the distance between the substrate 103 andthe second electrode 105 is constantly maintained, the second electrode105 may be separated from the supporting bar 102 b, the distance betweenthe substrate 103 and the second electrode 105 may be adjusted, andthen, the second electrode 105 may be disposed at the supporting bar 102b.

As another modified embodiment, the second electrode 105 may be moved bythe distance adjusting unit 102. That is, the distance adjusting unit102 may adjust the distance S2 between the second electrode 105 and thesubstrate 103 by raising or lowering the second electrode 105. In thiscase, the distance adjusting unit 102 adjusts the distance S1 betweenthe first electrode 104 and the substrate 103 by raising or lowering thesubstrate 103 with respect to the first electrode 104, and adjusts thedistance S2 between the substrate 103 and the second electrode 105 byraising or lowering the second electrode 105 with respect to thesubstrate 103 that is fixed.

The second electrode 105 is grounded. The second electrode 105 may havean internal space in which refrigerant flows. Since the refrigerantflows in the second electrode 105, it is possible to prevent the secondelectrode 105 from being overheated and to maintain the temperature ofthe second electrode 105 constant.

As described above, by adjusting the distance S1 between the substrate103 and the first electrode 104 that is the RF electrode, plasmauniformity is improved by adjusting the plasma status in the chamber101. Accordingly, the surface of an anode electrode (not shown) on thesubstrate 103 is uniformly etched so that it is possible to prevent thebrightness of an organic light emitting display device from beingdegraded and to increase the yield rate.

FIGS. 3A and 3B illustrate etching maps with respect to etching degreeof a mother substrate 203 that is plasma-processed by a conventionalplasma-processing apparatus. In more detail, the etching map of FIG. 3Ais a two-dimensional etching map, and the etching map of FIG. 3B is athree-dimensional etching map.

Referring to the etching map of FIG. 3A, it is apparent that the portionA of the surface of the mother substrate 203 is deeply etched butanother portion B is shallowly etched so that etching is not uniform.Brightness is relatively degraded at the deeply etched portion A,compared to the shallowly etched portion B. Also, a significantly andshallowly etched portion has a degraded lifetime.

FIGS. 4A and 4B illustrate etching maps with respect to etching degreeof a mother substrate 303 that is plasma-processed by the substrateplasma-processing apparatus 100 according to the embodiment of FIG. 1.In more detail, the etching map of FIG. 4A is a two-dimensional etchingmap, and the etching map of FIG. 4B is a three-dimensional etching map.

Referring to the etching maps of FIG. 4A, it is apparent that thesurface of the mother substrate 303 is uniformly etched. That is, thereis a small difference between the rather deeply etched portion A and therather shallowly etched portion B, and the whole surface of the mothersubstrate 303 is uniformly etched. In this manner, since uniform etchingis performed on the mother substrate 303, problems including brightnessdegradation and lifetime reduction of the organic light emitting displaydevice may be solved.

According to embodiments of the present invention, the etching in thesurface of the substrate is made uniform by maintaining plasmauniformity in the chamber constant, so that the problems includingbrightness degradation and lifetime reduction of the organic lightemitting display device are solved.

Although a few embodiments of the present invention have been shown anddescribed, it would be appreciated by those skilled in the art thatchanges may be made in this embodiment without departing from theprinciples and spirit of the invention, the scope of which is defined inthe claims and their equivalents.

What is claimed is:
 1. A method for manufacturing an organiclight-emitting display apparatus, the method comprising: placing asubstrate containing a display electrode in a plasma-processing chamberbetween first and second electrodes such that the first electrode withinthe chamber is disposed a first distance below and apart from thesubstrate and the second electrode within the chamber is disposed asecond distance above and apart from the substrate, the substrate beingsupported by a distance adjusting unit, the distance adjusting unitcoupling the second electrode to the substrate; adjusting at least oneof the first distance between the substrate and the first electrode andthe second distance between the substrate and the second electrode; andperforming plasma-processing while the substrate is disposed at theadjusted first and/or second distances apart from the first and secondelectrodes, the first and second electrodes not contacting the substrateduring plasma-processing.
 2. The method of claim 1, wherein the distanceadjusting unit comprises: a substrate supporting unit to support thesubstrate; a supporting bar coupled with the substrate supporting unitin a direction perpendicular to the substrate; and an actuator tovertically raise or lower the supporting bar.
 3. The method of claim 2,wherein the actuator is configured to adjust the first distance betweenthe substrate and the first electrode by moving the supporting bar in adirection away from a center of the chamber or by moving the supportingbar toward the center of the chamber.
 4. The method of claim 2, whereinthe second electrode is supported by the supporting bar.
 5. The methodof claim 4, wherein the second distance between the substrate and thesecond electrode is maintained constant while the substrate is raised orlowered.
 6. The method of claim 4, wherein, when the substrate israised, the first distance between the substrate and the first electrodeincreases and the second distance between the substrate and the secondelectrode decreases, and wherein, when the substrate is lowered, thefirst distance between the substrate and the first electrode decreasesand the second distance between the substrate and the second electrodeincreases.
 7. The method of claim 2, wherein the substrate supportingunit and the supporting bar comprise an insulating material.
 8. Themethod of claim 7, wherein the substrate supporting unit and thesupporting bar comprise a ceramic material.
 9. The method of claim 2,further comprising: a first insulating member disposed between thesubstrate supporting unit and the supporting bar, wherein the firstinsulating member couples the substrate supporting unit and thesupporting bar; and a second insulating member disposed between thefirst electrode and the chamber.
 10. The method of claim 9, furthercomprising a first cover unit externally surrounding the firstinsulating member.
 11. The method of claim 10, wherein the first coverunit comprises a ceramic material.
 12. The method of claim 9, whereinthe substrate supporting unit and the supporting bar comprise a metal.13. The method of claim 1, wherein the second electrode is grounded. 14.The method of claim 1, wherein refrigerant flows in the second electrodeto maintain a temperature of the second electrode.
 15. The method ofclaim 1, further comprising emitting a gas to the chamber through atleast one shower head, the gas being delivered by at least one pipe. 16.The method of claim 15, wherein a flow of the emitted gas is adjusted byat least one flow adjusting valve.
 17. The method of claim 1, whereinthe first electrode is disposed in an inner chamber, the inner chamberbeing disposed in the chamber.
 18. The method of claim 17, wherein athird insulating member is disposed between the inner chamber and thechamber.
 19. The method of claim 18, wherein a second cover unitexternally surrounds the third insulating member.
 20. The method ofclaim 19, wherein the second cover unit comprises a ceramic material.